Functional evaluation of peripheral nerve regeneration and target reinnervation in animal models: a critical overview

• Published in: The European journal of neuroscience 2016-02, Vol.43 (3), p.271-286
• Main Author: Navarro, Xavier
• Format: Article
• Language: English
• Subjects: Animals; Disease Models, Animal; electrophysiology; functional recovery; locomotion; Muscle, Skeletal - innervation; Nerve Regeneration; Neurologic Examination - instrumentation; Neurologic Examination - methods; Peripheral Nerve Injuries - rehabilitation; Peripheral Nerve Injuries - therapy; Recovery of Function; reinnervation
• ISSN: 0953-816X; 1460-9568
• DOI: 10.1111/ejn.13033

Peripheral nerve injuries usually lead to severe loss of motor, sensory and autonomic functions in the patients. Due to the complex requirements for adequate axonal regeneration, functional recovery is often poorly achieved. Experimental models are useful to investigate the mechanisms related to axonal regeneration and tissue reinnervation, and to test new therapeutic strategies to improve functional recovery. Therefore, objective and reliable evaluation methods should be applied for the assessment of regeneration and function restitution after nerve injury in animal models. This review gives an overview of the most useful methods to assess nerve regeneration, target reinnervation and recovery of complex sensory and motor functions, their values and limitations. The selection of methods has to be adequate to the main objective of the research study, either enhancement of axonal regeneration, improving regeneration and reinnervation of target organs by different types of nerve fibres, or increasing recovery of complex sensory and motor functions. It is generally recommended to use more than one functional method for each purpose, and also to perform morphological studies of the injured nerve and the reinnervated targets. An overview of the most useful methods to assess nerve regeneration, target reinnervation and recovery of sensory and motor functions in experimental models is provided. The methods have to be selected depending on the main objectives of the research study. For a multimodal approach, it is recommended to combine electrophysiological, locomotion and algesimetry tests that can be repeated along follow‐up, and add also morphological studies of the nerve and reinnervated targets.